Field of the Invention
The present invention relates to pallet racks typically utilized in distribution centers, warehouses and merchandising outlets for storing pallets typically loaded with goods.
Description of the Prior Art
In warehouses, the main function of storage racks is to store and support distribution of products from their facilities to customers or stores. Pallet racking is made of steel frames (uprights) for the vertical members and the horizontal members acting as load beams forming pallet decks. Typically the racks are arranged in flanking rows spaced apart a short distance and accessible from their outer edges by fork lifts traveling about fork lift bays to load and unload pallets from the respective pallet decks. Oftentimes commercially available pallets are deeper than the pallet racks resulting in the pallets overhanging both the inside and outside edges of the pallet racks. It is desirable to maintain spacing between the flanking rows of racks so it has become common practice to mount pallet stops on the inside edges of the pallet racks to act as stops to limit the extent to which the respective pallets will extend from the rear side of the racks.
Also, in some jurisdictions fire authorities require a minimum space between pallets on adjacent rows to leave an unencumbered vertical and horizontal space throughout the height and length of the rows to act as a flue in the event of a fire. It has thus become common practice to incorporate what is termed “row spacers” to maintain the desired spacing for these flues. The row spacers can range from 2″ wide to 36″ wide depending on the application. The amount and type (heavy duty or regular) of row spacer is determined by the engineer producing seismic or engineering calculations for the particular job.
Most of the row spacers on Selective Pallet racking are 12″ long or 18″ long. The reason for the most prevalent length of 12″ is based on a standard frame depth of 42″ and a standard pallet depth of 48″. The typical expectation in the past is the forklift driver would overhang the pallet across the two load beams by approximately 3″ on either side which would allow for an open space of 6″ between adjacent rows of pallets providing they were positioned properly with a 12″ row spacer in place.
The reality of working in a warehouse is that the pallet-put-away is often fast-paced, leaving the fork lift driver with little time to position the pallets precisely on the beams. Thus, when the pallets are placed on the beams the transverse distance can vary a few inches either way, often closing the width of the flue space mandated by the local fire authorities. Because the 6″ wide vertical flue extends the length of the racks is often encroached upon and in many cases rendered non-existent, some local fire authorities now require pallet stops. The pallet stops are an accessory pallet rack part that will stop a pallet at a fixed location to protect a 6″ longitudinal flue space to assure this space being open throughout the rack system.
As more municipalities and fire prevention authorities have enforced the 6″ unencumbered flue space requirement, several different styles of pallet stops have been developed. Examples of pallet stops offered by businesses entities include:
Single Bay Wraparound Style: A single bay wraparound style pallet stop employing a system of square tubes extending the length of a single bay and then at the end forming a 90 degree bend toward the rack to join a standard end connector where it is welded in place. These are typically spaced 3″ off the rear of the 42″ deep frame, thus stopping the pallet from going beyond this distance to cooperate in establishing a combined 6″ space from pallet to pallet carried on adjacent racks. One drawback of this system is that the stop extends into the flue area 1½″ per side, thus encroaching on the flue space mandated in many fire jurisdictions.
Z-Type: Another popular system sold by manufacturers is the Z-type bracket, which is 4″ to 6″ wide piece that is typically bolted in place to a bolt pattern in alignment with the center of the pallet. This has been approved by some fire authorities, but there have been issues due to insufficient integrity to withstand the pounding to which pallets are exposed, and bending to the rear, thus failing to function to properly stop the pallets to maintain the required spacing. The other issues with the Z-Type pallet stop is that if a pallet is placed on the top of the stop, the damage usually renders it useless for future loading. This Z-bracket can also be detrimental to the load beams supporting the pallets because it is typically of heavier gauge than the beam. When the load impacts the Z-bracket, it can damage the supporting load beam because the 14-16 gauge beams do not have sufficient structural integrity to withstand the abuse transmitted when a thicker gauge Z-bracket stop is impacted. Another disadvantage is the Z-bracket system is not adaptable to mounting on beams with different face sizes or bolt patterns thus presenting the challenge of inventorying and selection of the appropriate bracket for the particular application.
A modification of the Z-shaped stop incorporates a vertical mounting flange formed with a window to be slidably received over a transverse beam for convenient mounting of the stop. A device of this type is shown in U.S. Pat. No. 6,173,846 to Anderson. While such stops tend to serve their desired function, they are relatively expensive to manufacture, labor intensive to install and prone to damage.
Other efforts have led to a proposed horizontal, inverted, U-shaped bracket which is mounted to the longitudinal beams of adjacent racks to maintain the desired spacing and which may mount a sprinkler conduit between the adjacent racks. A device of this type is shown in U.S. Pat. No. 3,802,574 to Weider. A similar effort has recently led to a proposal that an inverted U-shaped member be mounted between the beams of racks to maintain the desired spacing. A device of this type is promoted by Rack Safety Products LLC of Aliso Viejo, Calif. These devices are also expensive to manufacture and install and, once installed, limit the maneuverability of the adjacent racks.
Further efforts have led to a proposal of an adaptor bracket configured with a universal mounting hole pattern for mounting a stop. A device of this type is shown in U.S. Patent Application No. 2014/0110547 to Consaul. Again, this device is relatively expensive to manufacture and install and does not seem to have gained commercial acceptance in the marketplace.
Consequently, there remains a need for a pallet stop system which is convenient and inexpensive to install which positively establish a continuous integral stop to limit pallet encroachment in the space between flanking rows of pallet racks. Preferably the system employs the expedient of mounting directly to commercially available racks to, when installed, establish the desired distance of the stop from the edge of the pallet decks or their loads.